Commercial carnosic acid (Fig. 1) was purchased from SigmaAldrich,
(USA C0609, carnosic acid from R. officinalis ≥91%, powder,
Lot #SLBK3241V); stock solutions of 1 mg/ml were prepared
in absolute ethanol. Gentamicina Larjan, P.10717 was purchased
from Laboratorio Veinfar I.C.S.A, Argentina and ciprofloxacin L6797-
4 from Norgreen S.A., Argentina.
All other reagents were of analytical grade. S. aureus clinical isolates
were obtained from pediatric patients with bacteremia reported
as methicillin resistant by the Service of Microbiology at
the Garrahan Pediatric Hospital (Argentina). The antibiotic resistance
profiles of MRSA clinical isolates used in this study is shown
in Table 1. The laboratory strain S. aureus ATCC 29213 was used as
control.